Missed on this combo?
I don't think you're wrong about the price.
How about a set of 59* W heads? They make W9's in that. They should flow buckets!
And costs buckets to convert to it. If the original build was budgeted to do something other than stock rocker offset, stock intake bolt location and stock header pattern you could make an argument for something in the W series. But IronMikes budget is hammered.
I hate to say it but I always tell my customers who want to make power, and make it RELATIVELY easily and inexpensively, then you need to start with a W-2 or better. After I bought my flow bench, I learned the truth about not living and and dying by flow numbers. The BEST stock rocker head will never make the power even the lowly W-2 will with a modern valve job. Yes, the initial cost is more. But it eliminates disappointment later on.
In 2001 I did a 408 that went 565 at 5200 RPM. It took fully ported Edelbrocks to do that, and with W-2's I could have easily made another 15-20 HP before I ever took a grinder to the W-2's. You can't just look at raw flow. You have to look at cross section. When you increase the displacement by 25% and engine speed by another 17-20% the stock cross section will never feed it. That means duration must go up, LSA must be closer and the intake manifold as big as you can get it.
Just my .02 on this and another THANK YOU to IronMike for publishing this. He may not care now, but he is edcuating everyone who sees this thread. Education is neither cheap, easy or quick. IronMike is giving all something free that many have paid for.